Lubricants



Patented Mar. 18, 1947 LUBRICANTS Lester W. McLennan, El Ccrrlto, Calif assigno to Union Oil Company oi California, Los Angelcs, Calii'., a corporation of California No Drawing. Application March 31, 1945,

. Serial No. 586,029

20 Claims. (Cl. 252--40.7)

This invention relates to lubricating compositions containing basic magnesium soaps and has special reference to basic magnesium soap greases. This application is a continuation-inpart of my copending application, Serial No. 469,894, filed December 23, 1942.

The object of the invention is to obtain all the benefits in such lubricants and greases as are peculiar to basic magnesium soaps. Basic magnesium soaps produce stable greases which have excellent melting point and penetration characteristics, do not require hydration, have exceptional resistance to deterioration by the action of heat and by the action of moisture, including boiling water, and have unusual thickening effects on lubricating oils, even at relative- 1y low concentrations. An especially important fact is that stable greases are formed with high viscosity oils of both parafiinic and naphthenic types in contrast to the inability of some basic soaps to effect proper thickening of both types of such oils. Another object of this invention is to provide processes for the manufacture of basic magnesium soap lubricants.

By the term basic magnesium soap as used in this application, it is meant to include products which are substantially neutral or substantially free from readily titratable excess alkalinity, at

least beyond a relatively small amount; and in which the ratio of equivalents of combined magnesium to equivalents of sa'ponifled higher molecular weight organic acids is greater than 1.1 to 1 and preferably is greater than about 1.2 to 1. Depending upon the particular saponifiable material and upon the characteristics of the mineral oil employed, it is preferred that this ratio be between about 1.2 to 1 and 2 to 1 but it may be as high as 3 to 1 or even as high as 4 to 1.

By the term "normal magnesium soap" as used in this application, it is meant to include those products which result when one equivalent of magnesium hydroxide or other basically reacting magnesium compound is reacted with one equiv-- alent of a saponifiable material to form a soap, said soap being the normal magnesium salt of the oxidation of petroleum fractions for example,

parafiin wax and mineral oil), rosin and related products, higher molecular weight naphthenic acids, sulfonic acids, etc., and saponifiable waxes such as beeswax, sperm oil, degras, etc.

The present invention resides in lubricating compositions, especially greases, which contain basic magnesium soaps which are substantially neutral or substantially free from readily titratable excess alkalinity. While the invention may be extended to freely fluid lubricants, such as Diesel engine lubricating oils containing small proportions of basic magnesium soaps, it includes more particularly the use of such basic magsoap greases have been found to have a ratio higher molecular weight organic acid, present as within the range of 1.3 to 1 and 1.9 to 1. The invention also comprises the method of making such lubricants.

The invention also includes the use of basic magnesium soaps to produce lubricants employing high viscosity mineral oils, e. g., 50 or SAE grade or even bright stocks as well as lower viscosity mineral oils, e. g., 20 or 30 SAE grade. Good lubricants may also be produced from the .very low viscosity bottoms fraction obtained by fractionating heavy alkylates obtained from alkylation processes in the manufacture of motor andaviation fuels from certain stocks where said bottoms have a viscosity in the order of that of spray oils or even lower. 1

In connection with the present basic magnesium soaps, it has been'found that under appropriate conditions it is possible to react one equivalent weight of a saponiiiable material (as determined by its saponiflcation number) with more than about 1.1 and up to about twice the equivalent weight (or even up to a ratio of 4, as above indicated) of a basically reacting magnesium compound, such as magnesium hydrate, to produce a material which is substantially neutral or free-from readily titratable excess alkalinity.

Although I do not wish to be limited by the Especially stable basic magnesium theories advanced herein. the net reaction which appears to occur and which results in the formation of the improved greases forming the subject of this invention is the oxidation of a portiori of the saponifiable material and reaction of the excess saponiflcation reagent with the acidic products formed. It is likely that the initial reaction which occurs is the formation of a normal magnesium soap by the saponiflcation of the saponifiable material with an equivalent amount of the basically reacting magnesium compound. Subsequently, a portion of the soap is oxidized by oxygen and the excess basically reacting magnesium compound present combines with the acidic materials formed The character of the oxidation reaction which occurs is undoubtedly influenced by the presence of the excess basically reacting magnesium compound and possibly by the presence of a polar solvent, such as water or glycerine. In this connection evidence has been obtained indicating that in the presence of a polar solvent "such as water, normal nesium carbonate and dispersing the resultant product in lubricating oil.

I have also discovered that basic magnesium soap greases can be formed, not only by the 'addition of normal magnesium soap and magnesi- V .um acetate to a lubricating oil or normal magaction products resulting from the combination of one equivalent of a magnesium oxide or magnesium hydroxide, with one-equivalent of a mineral acid or of an. organic acid of relatively low molecular weight. However, I may also employ acidic or basic salts in which one equivalent of magnesium oxide or magnesium hydroxide has magnesium soap forms a complex with magnesium hydroxide. This complex has a different solubility in oil than normal magnesium soap alone but still contains the magnesium hydroxide in a, readily titratable form. It is probable, therefore, that the material actually undergoing oxidation is the normal magnesium soap-magnesium hydroxide complex.

One of the principal oxidation products which results when one equivalent of a fat, saponifiable wax, or a higher molecular weight saponifiable organic acid is reacted with about 1.1 or more equivalents of a basically reacting. magnesium compound under the conditions as disclosed in the present invention and illustrated in the subsequent examples, is acetic acid present in the final product as magnesium acetate. In addition, appreciable amounts of carbon dioxide and relatively smaller amounts of other low molecular weight carboxylic acids, such as formic acid, propionic acid, oxalic acid, etc., also appear to be formed and are present in the final product as the corresponding magnesium salts. Under some conditions of oxidation coming within the scope of the present invention, magnesium carbonate may be the principal salt formed and may be preferred for certain combinations of mineral oil and saponifiable materials.

I have also discovered that basic magnesium soap greases having many of the desirable properties of basic magnesium soap greases formed by reacting, for example, -2.0 equivalents of a basically reacting magnesium compound with one equivalent of a fat, saponifiable wax, or a higher molecular weight saponifiable organic acid, can be obtained by mixing one moi of the normal magnesium soap of the same fat, saponifiable wax, or higher molecular weight saponifiable organic acid with lubricating oil, adding one mol of an aqueous solution of magnesium acetate and then heating to an elevated temperature tobeen reacted with more or less than one equivalent of a mineral acid or acid anhydride such as sulfuric acid, hydrochloric acid, orthophosphoric acid, pyrophosphoric acid, sulfurous acid, carbonic acid, boric acid, thiosulfuric acid, etc., S02, CO2, etc. I may also employ magneslum salts of organic acids of relatively low molecular weight which are relatively insoluble inlubricating oil. As examples may be cited the magnesium salts'of monocarboxylie and polycarboxylic acids containing less than about 7 carbon atoms per molecule, such as formic, acetic, propionic, valeric, oxalic, malonic, succinic, etc., acids, the low molecular weight alkyl and aryl sulfonic acids, the low molecular weight substituted carboxylic acids, such as glyceric, glycollic, thioglycollic, etc., acids, the low molecular weight phenolic and thiophenolic compounds such as phenol, cresol, thiophenol, etc.

In the case of greases coming within the scope of the present invention, I prefer to employ a complex of a normal magnesium soap with a metal carbonate or with a metal salt of a monocarboxylic acid having less than about 7 carbon atoms or a, mixture of any two or more of such complexes, either as such or in admixture with normal magnesium soap. In the case of greases to be used under acidic conditions, such as are encountered in the canning industry, it may be desirable to employ a complex of a normal magnesium soap with a magnesium oxide, or magnesium-hydroxide in conjunction with the preferred complexes listed above. It is also within the scope of my invention to incorporate an alkaline-type filler, such as zinc oxide in the finished grease in order to overcome the efiects of any acid liquors with which the greasesmay come in contact. In accordance with the present invention of using as lubricants basic magnesium soaps compounded in mineral oil, I prefer to employ more than 0.1 equivalent and preferably more than 0.2 equivalent and desirably between 0.3 and 0.9 equivalent and as high as 2.0 equivalents or even as much as 3.0 equivalents of a magnesium saltin conjunction with one equivalent of a normal magnesium soap as the basic magnesium soap to be'compounded with mineral oil to form the basic magnesium soap lubricants of the present invention. It is not meant to intimate that any give magnesium salt is the full equivalent of any other magnesium salt for modifying the characteristics of a dispersion of normal magnesium soap in lubricating oil. In fact, the complexes of various magnesium salts with a given normal magnesium soap vary over a wide rangeas regards their reably below about magnesium carbonate complex is more soluble in a given mineral oil than is a normal magnesium stearate-magnesium formate complex. Likewise, the latter complex appears to be more soluble than one formed from normal magnesium stearate and magnesium acetate. Complexes of a given normal magnesium soap with certain magnesium salts will posssess just the proper characteristics to form with a specific mineral oil a grease of the improved properties described herein. Other complexes of the same normal magnesium soap with different magnesium salts will be either too soluble or insuiilcicntly soluble to form desirable greases in the given mineral oil. In the latter case it is possible and desirable to form excellent greases coming within the scope of the present invention by mixing a complex which.is too soluble in the specific mineral oil with one possessing inadequate solubility. The exact proportions of the two complexes will depend upon the relative solubilities of the two complexes and can be readily determined by one skilled in the grease-making art.

It has also been noted that even though the final grease is to be substantially anhydrous, a product of improved characteristics can often be obtained by adding a small amount of water, for example, in the range of 0.1 to 3.0% by weight or even as high as by weight of the grease charge at' a suitable temperature and subsequently increasing the temperature to effect substantially complete dehydration. The grease may be at a temperature of about 210 F. or less when such water additions are made, although temperatures as high as 230 F. or even as high as 300 F. or higher may be used, and subsequent dehydration has been accomplished by heating to temperatures in the neighborhood of 250 F. or higher when necessary. With certain saponiiication reagents the greases produced by the processes oi the present invention have a granular appearance, but by employing the hydration-dehydration technic, products of smooth buttery texture are obtained often accompanied by an increase in consistency and melting point. Further improvements in grease texture can likewise usually be obtained by working the grease at temperatures below about 200 F. and prefer- 150 F. prior to final packaging.

Normally in reacting a saponifiable material with an excess of a basically reacting magnesium compound the extent of the oxidation reaction is controlled so as to produce a final grease which is substantially neutral or free from readily titratable excess alkalinity, that is, one having a free acid or free alkali content less than about the equivalent of 5.0 mg. KOH per gram of soap present. In other words, the oxidation is so controlled that it results in the formation of at least about 0.1 equivalent of acidic oxidation prodnets and preferably about 0.2 to 1.0 equivalent of acidic oxidation products or even as high as about 3.0 equivalents of acidic oxidation products. The progress of the oxidation reaction can be followed by periodically titrating to determine the proportion of magnesium hydroxide present in the reacting mass, which was not combined with acidic oxidation products and when this has reached the desired value, the oxidation may be arrested such as by rapidly cooling to a temperature below about 250 F. to 300 F. While it is preferred that the soaps in greases of this invention be substantially neutral, they may contain a small amount of free acidity or alkalinity.

The finished grease may have a free-alkali contentcalculated as magnesium hydroxide as high as about 0.5% by weight of grease or a free acid content equivalent to about 2.0 mg. KOH per gram of grease. A grease having a free acid content may be obtained by either continuing the oxidation to produce an excess of acidic reaction products over that required to neutralize the free magnesium hydroxide or the oxidation reaction can be stopped at an earlier stage, such as while free magnesium hydroxide is still present, and fatty acid or other acidic materials added in sufficient quantity to give a grease oi the desired free acid content. In order to obtain a free alkali content the oxidation can be stopped at an intermediate point r it can be continued to produce a substantially neutral or even acidic soap and the desired excess of free magnesium hydroxide then added.

Usually the hydration-dehydration technique to produce a final substantially anhydrous grease is most effective on a slightly acidic basic magnesium soap grease. Subsequently the grease can be adjusted to the desired acidity or alkalinity by the addition of magnesium hydroxide or acid, as the case may be. In a similar manner basic soap greases prepared by compounding normal magnesium soaps with magnesium salts can be rendered acidic or alkaline as desired by adding fatty acids or other acidic materials or .magnesium hydroxide or other basically reacting magnesium compounds, as the case may be.

Free alkalinity is measured in accordance with A. S. T. M. method of test No. D-128-40, section 18, except that titration is conducted in the cold and the titration is made directly with standard HCi solution rather than by adding an excess of HClsolution and then back titrating with alcoholic potassium hydroxide solution. Free acidity is measured in accordance with A. S. T. M. method of test No. D-128-40, section 20. Briefly, the methods of test employed are as follows:

A '10 gram sample of the grease is weighed to the nearest tenth of a gram into a 250 ml. Erlenmeyer flask. To the flask is then added 75 ml.

required. Free alkalinity is calculated in terms of magnesium hydroxide; free acidity in terms of oleic acid or acetic acid. Free alkalinity and free acidity may also be expressed in terms of equivalent mg. of KOH per gram of grease or soap as desired.

Since the formation of basic magnesium soaps from a fat, saponifiable wax or higher molecular weight saponifiable organic acid and an excess of a basically reacting magnesium compound in part involves an oxidation reaction, it is-necessary that thisreaction be conducted in the presence of air or other oxygen-containing gas. Further, preferably, the reaction should be conducted in the presence ofa polar solvent such as, for example, water or glycerine. If desired, a portion or all of the mineral oil can be blended the'b' sically reacting magnesium compound subseque tly conducted. Under these conditions the mineral oil appears to serve essentially only as an inert diluent. Onthe other hand, the

' saponifiable material can be reacted with the.

basically reacting magnesium compound in the absence of mineral oil thereby forming a concentrate which can be subsequently compounded with mineral oil to form a grease. When a basic 1 magnesium soap or basic magnesium soap grease isto be formed by reacting-a normal magnesium soap with a magnesium salt or a mixture of magnesium salts, similar procedures can be followed except that the-presence of oxygen-containing gas is not necessary and may even be undesirable; on the other hand, it does appear preferable at some stage in the compounding procedure to have a polar solvent present in order to effect formation of the molecular complex from the normal magnesium soap andmagnesium salt.

As indicated hereinabove, in order for the de-' sired oxidation reaction and normal magnesium soap-magnesium salt complex formation to proceed within the preferred temperature range it is usually desirable that at least a small percentage of a polar solvent, in the neighborhood of at least about 0.1% by weight of the reacting mass, be present. Further, it appears that preferably this polar solvent should be water, although under some conditions the oxidation and complex formation proceeds more readily in the presence of a mixture of water and glycerine, water and glycol, or with some hydroxy or polyhydroxy organic compound, such as ethyl alcohol, di-

but under some conditions smaller quantities,

such as about 0.1% and higher quantities, such as about can be used. As an indication of the desirability of having at least a small percentage of a polar solvent present, I have observed in the case of certain anhydrous .normal magnesium soaps that when mixed with anhydrous magnesium hydroxide and heated in the presence of oxygen-at a temperature of 350 F. to 500 F. for three hours and the mixture subsequently analyzed, it was found that little or no reaction had occurred and substantially all of the magnesium hydroxide could be recovered unchanged. Further, if the same mixtures containing an added 0.5% of water were heated in a closed kettle under the same conditions but with oxygen excluded, little or no reaction was observed to take place. However, when the same mixture containing 0.5% of added water was heated for three hours in contact with air or oxygen and at a temperature of 350 F. to 500 F.. the resulting product contained normal magnesium soap along with magnesium carbonate and the magnesium salts of organic acidic oxidation products, and a correspondingamount of the magnesium hydroxide had disappeared.

One of the preferred methods of forming basicmagnesium soap lubricants from a normal magnesium soap, a magnesium salt, and mineral oil is to dissolve the normal magnesium soap in all or only a portion of the mineral oil to be used and subsequently add a solution or a dispersion of the .sium compound, such asmagnesium oxide, or

magnesium hydroxide by methods known to those skilled in the art.

Another preferred method of forming a basic magnesium soap lubricant from a normal magnesium soap, a magnesium salt, and 'mineral oil is to dissolve the desired normal magnesium soap in mineral oil or form the normal magnesium soap from the desired saponifiable material and a basically reacting magnesium compound such as magnesium oxide or magnesium hydroxide in the presence of all or a part of the desired mineral oil. Subsequently, a complex is formed between the normal magnesium soap and magnesium oxide or magnesium hydroxide, added in an amount equivalent to the amount of salt which it is desired to complex with the normal magnesium soap, in the manner described in the preceding paragraph, except that the polar solvent need not be removed. Finally the acid of the desired salt in' an amount equivalent to the added magnesium oxide or magnesium hydroxide is introduced and all or a part of the polar solvent, then removed by heating to a temperature within the range of about 200 F. to 600 Additional mineral oil can beadded at any or all stages of the compounding as will be obvious to one skilled in the art. 1

As a special case of the preferred method described in the preceding paragraph, the desired saponifiable material can be reacted with an amount of a basically reacting magnesiumcompound such as magnesium oxide or magnesium hydroxide equal to that required to react with the saponifiable material and with the acid whose magnesium salt is desired in the complex. After the saponificatlon has been completed the acid of the desiredmetal salt can be added in quantity just sufficient to neutralize the excess magnesium oxide or magnesium hydroxide present. It is also possible under this special case to mix the desired saponifiable material with the acid whose magnesium salt is desired in the complex and then add an amount of magnesium oxide or magnesium hydroxide or other basically reacting magnesium compound sumcient to finally effect the saponification, form the salt and produce the complex. If it is desired to produce a final product having a free alkali or free acid content the desired acidity or alkalinity can be introduced at any of several stages as will be obvious to one skilled in the art.

It is of particular interest to note that the greases constituting the subject of this invention can usually be produced as substantially anhydrous products having a stable grease structui' However, under some conditions and in order to obtain certain specific characteristics it may be desirable to produce greases containing small amounts of water, for example less than about 1.0% and preferably less than about 0.5%. It

will be obvious to one skilled in the art that this amount of water can be incorporated at any of several stages in the process of making the grease. For example, if the grease has less than the desired amount of water, the required additional water can be added and worked into the grease at a temperature of 200 F. or less prior to drawing. On the other hand, if desired, an

excess of water can be added to the grease before or-after all of the oil has been incorporated or even during addition of oil and when the temperature is in the neighborhood of 210 F. or less or even at more elevated temperatures such as 220 F. to 300 F. and the excess water subsequently removed by increasing the temperature of the grease if necessary and then cooling after the desired water content has been reached.

The formation of the basic soap greases of this invention generally requires high temperatures,

preferably in the region of about 400 F. to 550 F., although'they can be formed over a wider temperature range such as about 300 F. to 600 F. In forming normal magnesium soaps and basic magnesium soaps by reacting a saponifiable material with a basically reacting magnesium compound, the base is added preferably as the hydroxide (Mg(OH)2) or as magnesium hydrate (Mg(OH)2.8H2O) although in some instances magnesium oxide, magnesium carbonate, etc., may be employed. The base may be added as a powder, small granules, or as an aqueous or oil slurry, as desired. Either normal or basic magnesium soap formation is preferably carried out in the presence of part of the lubricating oil to be used in the finished grease, although inert low-boiling solvents may be used under pressure and subsequently evaporated to leave a pure soap residue. Particularly in the case of normal magnesium soaps it is entirely possible to prepare dry soap powder by reacting, for example, oleic The amount of basic magnesium soap to be I incorporated in the greases of this invention may be from about 5% to about 50%, although concentrations as low as about 2% and as high as about 75% may be desirable for certain special combinations and applications.

Basic magnesium soaps may also be used in relatively small proportions to produce liquid greases and fluid lubricants, such as lubricating oils for internal combustion engines, especially Diesel engines. The soap concentrations in such applications are usually below about 5% and are normally in the range of 0.2% to about 2.0%. However, as indicated in one of the subsequent examples by a proper choice of saponifiable material, magnesium salt, and mineral oil, it is possible to produce a fluid lubricant containing as high as by weight of basic magnesium soap or even higher.

Materials other than basic magnesium soaps may also be added to the lubricating compositions of this invention, such as water, alcohols, and other solvents, anti-oxidants, fillers, etc., as desiderd. An especially hard grease, for example, was prepared by the incorporation of an oil containing about 40% of asphalt instead of the usual lubricating oil to yield a grease composition similar to that of the subsequent example below. Additions of petrolatum and solvent extracts from lubricating oil stocks have been helpful in some instances.

In addition to using both light and heavy mincral lubricating oils to make basic magnesium soap lubricants, 'I"may also employ the light lubricating-type oil which is recovered as heavy bottoms from the distillation of residuals obtained in modern alkylation processes employed in making alkylated motor fuels from some stocks. In some such processes the mentioned residuals are recovered in fairly large proportions. About thereof is then distilledofi to v be used for various purposes, thereby leaving about 20% of the heavy alkylated bottoms mentioned. This 20% fraction may be further out to yield lighter and heavier fractions. These fractions have viscosities in the order of that of spray oil and of very light lubricating oil, e. g., SAE 10. In view of the properties of the basic magnesium soaps hereof such heavy alkylated bottoms may be. used as-the lubricating fraction, especially where. a light oil is desirable for a given fluid ,or grease-likeproduct having a low ltl'rample I A basic magnesium soap grease was prepared from the following ingredients:

. Grams Tallow fatty acids 100.0 Acetic acid 21.5 Magnesium hydroxide 21.0 SAE 50 grade V. I. Oil 400 The tallow fatty acids were charged to a large beaker, melted, subsequently mixed with 50 grams of oil and heated. When the temperature of the mixture was -F., the acetic acid was added and followed by the magnesium hydroxide in the form of an aqueous slurry. While stirring, the temperature of the material was gradually increased to effect reaction and partial dehydration and the remaining oil gradually added. The

mixture was finally heated to a temperature of 400 F. and then set aside to cool to room temperature. The cooled material was worked to a. smooth. unctuous grease. This substantially anhydrous neutral product had a ratio of equivalents of combined magnesium to high'molecular weight fatty acids of 2.0.

Example II Approximately 100 grams of tallow fatty acids (0.36 gram equivalent), 10 grams of glycerine, 19.3 grams of magnesium hydroxide (0.68 gram equivalent), and 100 grams of water were mixed in an open beakerand heated to eflect reaction and remove the water. Heating was continued to a temperature of 400 F. and the temperature maintained at this value for a period of 4 hours. At the end of this time the product contained substantially no free magnesium hydroxide. 100 grams of the resultant product was mixed with 400 grams of a paraflinic oil having a viscosity of 600 Saybolt Universal seconds at 100 F., and the mixture heated to 400 F., followed by cooling to room temperature and working. An anhydrous, substantially neutral grease having a smooth buttery 'texture was obtained. The ratio of equivalents of combined magnesium to high molecular weight organic acids was 1.90. 3

Other modifications of this invention will be apparent to those skilled in the art.

While the foregoing description of one embodiment of my invention has been made in connection with the preferred use of magnesium salts of mineral acids and organic acids of relatively low molecular weight in coniunctionwith normal magnesium soaps and mineral oil to form basic magnesium soap greases, I may also form.

salts useful for this purpose include the salts of sodium, potassium, lithium, calcium, barium, strontium, aluminum, beryllium, zinc, cadmium, boron, tin, titanium, zirconium, cerium, vanadium, antimony, bismuth, arsenic, copper,

. 12 6. A lubricating composition according to claim '1, in which the magnesium soap complex comprises a normal magnesium soap and a metal salt of mineral acid and in which the ratio of equivalents of metal salt to equivalents of normal magnesium soap is between about 0.2 and 2.0.

7. A lubricating composition according to claim- 1, in which the magnesium soap complex compriles a normal magnesium soap and a metal salt of low molecular weight organic acid and in which the ratio of equivalents of metal salt to equivalents of normal magnesium soap is between about 0.2 and 2.0.

molybdenum, caesium, germanium, columbium,

chromium, selenium tellurium, tungsten, manganese, iron, cobalt and nickel.

The incorporation of the metal salt in the grease may be made in accordance with the methods outlined herein for the incorporation of the magnesium salts or, if desired, in many cases the metal salts may be produced by adding the metal oxide or hydroxide to a normal magnesium soap and subsequently heating to an elevated temperature to effect oxidation of a small proportion of the normal magnesium soap to yield low molecular weight acidic products which in turn are neutralized by the metal oxide or hydroxide present and resulting in the formation of the basic magnesium soap lubricants of this.

invention.

- The foregoing description of my invention is not to be taken as limiting my invention but only as illustrative thereof since many variations may be made by those skilled in the art without departing from the scope of the following claim I claim;

1. A lubricating composition comprising min eral oil and magnesium soap complex, the latter being a molecular complex containing a ratio of equivalents of magnesium to equivalents of saponified high molecular weight organic acidsbetween about 1.1 and 4, and being substantially free from readily titratable excess alkalinity.

2. A lubricating composition comprising mineral oil and magnesium soap complex, the latter being a molecular complex containing a ratio of equivalents of magnesium to equivalents of saponifled high molecular weight organic acids between about 1.1 and 4, and being substantially 8. A lubricating composition according to claim 1, in which the magnesi t im soap complex is made by reacting in excess of one equivalent of a basically reacting magnesium compound with one equivalent of a saponiflable material.

9. A lubricating composition according to claim 1, in which the magnesium soap complex is made by admixing normal magnesium soap and a metal salt of mineral acid.

-' 10-. A lubricating composition according toclaim 1, in which the magnesium soap complex is made by admixing normal magnesium soap and a metal salt acid. I

11. A lubricating composition according to claim. 1, in which, the magnesium soap complex basically reacting magnesium; compound.

equivalents of metal salt to equivalents of normal magnesium soap is greater than about 0.1.

5. A lubricating composition according to claim 1,-in which the magnesium. soap complex comprises a normal magnesium soap and a metal salt of a low molecular weight organic acid and Q in'which the ratio of equivalents of metal salt to equivalents of normal magnesium soap is greater than about 0.1. V

is made b'y'reacting normal magnesium soap. basically reacting magnesium compound and -a mineral acid theamount of mineral acid being sufficient to neutralize said basically reacting magnesium compound.

12. A lubricating composition according to claim 1, in which the magnesium soap complex is made by reacting normal magnesium soap, basically areacting magnesium compound and a low molecular weight organic acid, the amount 01, said acid being sufllcient to neutralize said 13. A lubricating composition according to claim 1, in which the magnesium soap complex is made by admixture of normal magnesium soap and a magnesium salt of a mineral acid.

14. A lubricating composition according to claim 1, in which the magnesium soap complex is made by admixture of normal magnesium soap and a magnesium salt of a low molecular weight organic acid.

15. A lubricating composition according to claim 1, in which the magnesium soap complex comprises a mixture of normal magnesium soap and magnesium acetate.

16. Av lubricating composition according to.

claim 1, in whichthe magnesium soap complex comprises a mixture of normal magnesium soap and magnesium carbonate.

1'7. A lubricating composition according to claim 1, in which the magnesium soap complex comprises a mixture of normal magnesium soap, metal salt of mineral acid and metal salt of low molecular weight fatty acid.

18. A lubricating composition according to claim 1, in which the magnesium soap complex comprises a mixture of normal magnesium soap, metal carbonate and a metal acetate.

19. A lubricating composition according to claim 1, in which the magnesium soap complex comprises a mixture of normal magnesium soap, magnesium carbonate and magnesium acetate.

20. A method of preparing lubricants comprising reacting a saponifiable material with more than one equivalent of a basically reacting magnesium compound in the presence of mineral oil of a low molecular weight organic 13 and in the presence oi oxygen at temperatures between approximately 400 F. and 550 F. to yield a magnesium soap complex, cooling and adding additional mineral oil, said magnesium soap complex being substantially neutral as indicated by titration and containing a ratio of equivalents of magnesium to equivalents of saponifled high molecular weight organic acids in excess 01 about 1.1.

LESTER W. McLENNAN.

REFERENCES crran UNITED STATES PATENTS Name Date Ott et al. Mar. 10, 1936 Number Number Name Date 2,154,383 Ott et a1. a Apr. 11, 1939 2,197,263 Carmichael et al. Apr. 16, 1940 2,303,256 Cameltord Nov. 24. 1942 FOREIGN PATENTS Number Country Date 3,603 British 1873 OTHER REFERENCES Boner. Metallic Soaps for Thickening Mineral Oils, Article in Industrial and Engineering Chemistry, Jan. 1937, vol. 29, pp. 58, 59, and 60.

McLennan, Methods of Compounding Barium 15 Greases, Their Properties, .Uses and Future,

Article in the National Petroleum News,

7 April 5, 1944, pages R-234, R-236, R-238 and 

